This invention relates generally to the removal of sensible and latent heat from air and more particularly to methods and means to do so while minimizing the consumption of energy.
The hoary expression: "It ain't the heat, it's the humidity", reflects the failure of the body to cool itself by perspiring on humid days. Conventional air conditioning apparatus passes all the air to be conditioned over a cool evaporator coil [ordinarily at 4.4.degree.-7.2.degree. C. (40.degree.-45.degree. F.)] not only reducing the air temperature (sensible heat removal), but also causing a substantial part of the water vapor (or latent heat) to be removed as condensation. The latter is often accomplished too well, resulting in excessively dry air whether required for comfort or not.
This excessively dry air is indicative of excessive consumption or waste of energy. That is, when the sensible heat is brought to a desired level, the humidity is lower than necessary, and it requires the expenditure of energy to achieve this undesired extra low humidity.
It has been reported that even at a relatively high dry bulb temperature of 25.5.degree. C. (78.degree. F.) the vast majority of people will be fairly comfortable when the relative humidity is as high as 60 to 70 percent.